The present invention is in the field of plumbing, and more specifically relates to a tool to facilitate gripping and applying torque to a free end of a piece of pipe or tubing.
Although the present invention is relatively simple, a search of the prior art failed to discover a device having its essential features.
In U.S. Pat. No. 3,448,772, Delamater shows a waste pipe plug of a plastic material that includes a plug portion and a stop collar, but does not include a handle or anvil.
In U.S. Pat. No. 2,321,667, Foster shows a stopper for use with gas mains. Although a portion of the stopper fits into a pipe, the patented device bears little resemblance to the present invention.
In U.S. Pat. No. 2,279,118 issued to Fortune, et al., there is shown a plug that can be screwed into the end of a pipe for the purpose of lifting the pipe. This pipe is used in the oil industry.
In U.S. Pat. No. 3,200,984, Fueslein, et al., show a pressure seal plug that is made of a resilient deformable material such as nature and synthetic rubber, as well as certain plastics.
In U.S. Pat. No. 4,899,409, Cox, Jr., shows a manual tool that is useful in preparing the end of a tube for joining it to another tube.
The tool of the present invention finds its greatest use in the field of plumbing and pipe fitting, where it is some times necessary to unscrew a length of pipe from some type of fitting to which it has been screwed. Typically, the piece of pipe has corroded so that the threaded end is difficult to move with respect to the fixture. Opposite the threaded end is a free end, to which a wrench or pliers are to be applied for the purpose of applying torque to the length of pipe.
The specific problem is that if one grips the free end tightly enough to permit the necessary torque to be applied, there is a strong likelihood that the pliers or wrench will damage the free end of the pipe, particularly if the free end is also corroded. The problem also arises when the wall of the pipe is relatively thin as in the case of tubing. As will be seen below, the tool of the present invention permits the pipe or tubing to be gripped very tightly by a wrench or pliers without, at the same time, damaging the free end.